>Doesn’t this information come from the database? ?
>Does this mean that NSFetchedResultsController itself needs other types of indexes besides database indexes?
>What really happened when NSFetchedResultsController set the cache?
>Is caching only useful for static data? If my data is updated frequently, should I use the cache?
>How do I analyze the performance of the cache? I tried caching, but I didn’t see any performance improvement. I timed-performFetch: but saw the time increase from 0.018 seconds (without caching) to 0.023 seconds (with caching). I also timed-objectAtIndexPath: and only time from 0.000030( Without caching) is reduced to 0.000029 (with catch).
In other words, I want to know when (or not) caching improves performance and why.
As @Marcus below As pointed out, “500 entries are small. Core data can process it without human noticeable lag. Use caching when you have thousands of records.” So I think there are very few applications that can use caching from
It is a “copy” of the data in the database, and it is very useful when the next instantiation of the NSFetchedResultsController The easy-to-use format is serialized to disk.
In other words, it is the final result of flash freezing to disk.
Of course I read a PhD , But I don’t quite understand the meaning of “set any part and order content”.
>Doesn’t this information come from the database?
>Does this mean that NSFetchedResultsController itself needs other types of indexes besides database indexes?
>What really happened when NSFetchedResultsController set the cache?
>Is caching only useful for static data? If my data is updated frequently, should I use the cache?
>How do I analyze the performance of the cache? I tried caching, but I didn’t see any performance improvement. I timed-performFetch: but saw the time increase from 0.018 seconds (without caching) to 0.023 seconds (with caching). I also timed-objectAtIndexPath: and only time from 0.000030( Without caching) is reduced to 0.000029 (with catch).
In other words, I want to know when (or not) caching improves performance and why.
As @Marcus below As pointed out, “500 entries are small. Core data can process it without human noticeable lag. Use caching when you have thousands of records.” So I think there are very few applications that can use caching from
The cache of NSFetchedResultsController is a shortcut. It is the cache of the final result of NSFetchRequest. It is not the whole data, but enough data of NSFetchedResultsController, The results can be displayed quickly; very quickly.
It is a “copy” of the data in the database, and it is serialized to disk in a format that is easy to use when NSFetchedResultsController is next instantiated.
In other words, it is the final result of flash freezing to disk.